Messages in this thread | | | Subject | Re: [PATCH 1/4] xen/PVH: Replace GDT_ENTRY with explicit constant | From | Boris Ostrovsky <> | Date | Tue, 1 May 2018 08:40:20 -0400 |
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On 05/01/2018 07:31 AM, David Laight wrote: > From: Boris Ostrovsky >> Sent: 30 April 2018 17:24 >> To: linux-kernel@vger.kernel.org; xen-devel@lists.xenproject.org >> Cc: jgross@suse.com; Boris Ostrovsky; stable@vger.kernel.org >> Subject: [PATCH 1/4] xen/PVH: Replace GDT_ENTRY with explicit constant >> >> Latest binutils release (2.29.1) will no longer allow proper computation >> of GDT entries on 32-bits, with warning: >> >> arch/x86/xen/xen-pvh.S: Assembler messages: >> arch/x86/xen/xen-pvh.S:150: Warning: shift count out of range (32 is not between 0 and 31) >> arch/x86/xen/xen-pvh.S:150: Warning: shift count out of range (40 is not between 0 and 31) >> arch/x86/xen/xen-pvh.S:150: Warning: shift count out of range (32 is not between 0 and 31) >> arch/x86/xen/xen-pvh.S:152: Warning: shift count out of range (32 is not between 0 and 31) >> arch/x86/xen/xen-pvh.S:152: Warning: shift count out of range (40 is not between 0 and 31) >> arch/x86/xen/xen-pvh.S:152: Warning: shift count out of range (32 is not between 0 and 31) >> >> Use explicit value of the entry instead of using GDT_ENTRY() macro. > ... >> #ifdef CONFIG_X86_64 >> - .quad GDT_ENTRY(0xa09a, 0, 0xfffff) /* __KERNEL_CS */ >> + .quad 0x00af9a000000ffff /* __BOOT_CS */ >> #else >> - .quad GDT_ENTRY(0xc09a, 0, 0xfffff) /* __KERNEL_CS */ >> + .quad 0x00cf9a000000ffff /* __BOOT_CS */ >> #endif >> - .quad GDT_ENTRY(0xc092, 0, 0xfffff) /* __KERNEL_DS */ >> + .quad 0x00cf92000000ffff /* __BOOT_DS */ >> gdt_end: > > It has to be possible to fix the GDT_ENTRY() macro. > Even if you end up with one that generates two 32bit values.
Is it worth it though? We seem to be using GDT_ENTRY_INIT() everywhere and the only other reference that I see is in pm.c and it also probably ought to use GDT_ENTRY_INIT().
> > You've also changed the name in the comments.
Yes, I should mention this in the commit message.
-boris
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